http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50075
--- Comment #2 from Kerrek SB <z0sh at sogetthis dot com> 2011-08-13 14:09:20 UTC --- Indeed, according to the FDIS size() is *not* constexpr, but I had initially just checked the GCC implementation, in which it *is* declared as constexpr! (This is in "c++/4.6.1/initializer_list".)
